Windows Server 2003 was based on Windows XP and was released in four editions: Web, Standard, Enterprise and Datacenter. It also had derivative versions for clusters, storage and Microsoft’s Small Business Server. Important upgrades included integrating Internet Information Services (IIS), improvements to Active Directory (AD) and Group Policy (GP), and the migration to Automated System Recovery (ASR).
TRUSTED BY
http://www.microsoft.com/download/en/details.aspx?displaylang=en&id=18465
From there you can open the logging on the domain controller to find the event ID generated for the failed logon if you have auditing enabled. This will tell you the originating computer the lock came from and the type of logon process.